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Author: Yung-Chieh Hung (2007-03-13); recommendation: Yeh-Liang Hsu (2007-03-13).
Note: This article is Chapter 1 of Yung-Chieh Hung’s PhD thesis “Development of an Innovative Patent-based Design Methodology.”

Chapter 1. Introduction

1.1  An innovation design method based on design-around approach

Design process plays an important role to the success of a product’s development. Design process influences performance, quality, cost, and the development time of the product. Most researchers in design process try to establish a structured model to describe or facilitate design by dividing the design process into several sequential phases, based on the essential activities that the designers perform or should perform. These activities are often presented in a flow chart manner, with feedback loops showing the iterative returns to the earlier phases. Ulrich and Eppinger [1995] pointed out that structured design process models are valuable because they make the decision process explicit, they act as “checklists” of the key steps in a development activity, and they are largely self-documenting.

Systematic product design processes commonly seen in research literature or design textbooks often start with finding a need, specification development, conceptual design, detail design, to production. Such design processes are very useful for innovative design. Innovative design mythologies such as analogy, brain storming, and TRIZ (Theory of Inventive Problem Solving) are often used to generate the design solutions. However, the design problem constantly faced by engineering designers across industries is how to design around existing patents [Glazier, 1990], which requires a completely different design approach and knowledge. This type of design problem is often a local innovation of an existing patent. The rules of patent infringement judgment present the major constraints to such design problems, and designers may have to sacrifice the performance of the product in order not to infringe on existing patents.

Although patent analysis has almost been a standard process in the early stage of product development in industry, few researches in design processes consider competition or constraints in the form of existing patents or fully utilized the information obtained from patent analysis. Chen and Chen [2004] integrated the systematic design process and design patent protection mechanism to develop an adaptive design process. Zhang and Chen [2004] presented a process based upon the extension theory and TRIZ to design around patents and resolve conflictive problems. Chang et al. [2004] proposed an auxiliary methodology for creative mechanism design. This methodology is a systematic approach based on modification of existing devices for the generation of all possible topological structures of mechanisms to avoid existing designs that have patent protection.

An innovative design process is analogous to an unconstrained optimization problem. The goal is to maximize the performance of the design. Existing patents are often the most difficult constraints faced by engineering designers in industry. This type of design problem can be analogous to a constrained optimization problem. In the design process, priority is given to avoiding infringement with other existing patents, even though the performance of the design may have to be sacrificed.

In a constrained optimization problem, the optimum point often occurs on the boundary of the feasible domain. Similarly, a new design is often inspired by an existing product or technology, and a new product is often generated by designing around an existing patent. Through construing and analyzing existing patents and comparing the disclosure of patents, time and cost for new product development can be greatly reduced. Moreover, design process based on designing around current patents can assist designers to evade the patent traps and to avoid patent infringement.

Designing around is based on the process and rule of the patent infringement judgment to develop the design that has the substantial difference with the scope of claims of existing patents. Morgan, Lewis & Bockius LLP [2000] proposed five approaches for designing around granted patent:

(1)       Investigate the file wrapper to study which scope of claims has been surrendered by the patent holder during the prosecution.

(2)       Apply the prior art.

(3)       Eliminate one or more claimed technological characteristics.

(4)       Change the functions or objectives of technological characteristics.

(5)       Use the techniques mentioned in thebackground of the inventionof the specification since these techniques have been considered as nonequivalent to those in the claims.

Nydegger and Richards [2000] proposed three possible strategies for designing around an existing patent:

(1)       Reduce the number of elements in the claims to satisfy the full elements rule.

(2)       Use the method of substitution to make the accused subject matter different from the techniques disclosed in the claims to prevent literal infringements.

(3)       Substantially change one of the constitutive requirements of way/function/result to prevent infringements according to the doctrine of equivalents.

These designing around methods provide a good guideline for avoiding patent infringement. Note that each of the methods described above presents a new design problem to be solved. Innovative design methodologies are still needed to generate real engineering solutions for the new design problems.

1.2  Purpose of this research

This research proposes a patent-based design process by systematically integrating patent information, the rules of patent infringement judgement, strategies of designing around patents, and the innovation design methodology. The purpose of this design process is to assist enterprises to enhance the efficiency of product development, lower the possibility of patent infringements, and increase the patentability of results of innovation.

Based on the discussion in the previous section, we hope to achieve 4 goals with this design process:

(1)      Fully utilize patent information in the design process.

(2)      Consider how patent infringement can be avoided before working on generating a new design.

(3)      Generate a new design based on designing around existing patents.

(4)      Use innovative design methodology such as TRIZ to facilitate the generation of a new design concept.

Figure 1 shows the conceptual flowchart of this patent-based design process. To start with, the designer conducts standard patent search and analysis to identify the related patents to be designed around and to collect functions and core techniques of each related patent. Each patent is then symbolized by a “design matrix” converted from the design parameters and functional requirements of the patent. This design matrix representation is inspired by the “axiomatic design” methodology proposed by Suh [2001], and will be discussed in later chapters.

The design matrices of the patents can be manipulated mathematically. Rules of infringement judgment and design around strategies can be converted into mathematical operators of the design matrices. In this research, a design-around algorithm is developed to generate a new design matrix that does not infringe with design matrices of existing patents. There can be many solutions that satisfy the constraints. In our algorithm, the design matrix which is the smallest variation of one of the design matrices of existing patents to be designed around will be chosen first. The new design represented by this design matrix will also be a local variation of an existing patent.

Based on this existing patent, TRIZ is used to transform the new design matrix back into a real engineering design. However, this transformation may fail because there may not be a feasible design corresponding to the new design matrix generated by the algorithm. If TRIZ fails to generate a feasible design, the algorithm is triggered again to generate the next design matrix which satisfies the constraints and is the smallest variation of one of the design matrices of the existing patents. Finally, a new design concept is generated.

Figure 1. Conceptual flowchart of the patent-based design process.

1.3  Organization of the dissertation

The rest of the dissertation is organized as follows. In chapter 2, a brief introduction to TRIZ (Theory of Inventive Problem Solving) is presented. Then a novel design concept for a total knee prosthesis is generated to demonstrate the application procedure of TRIZ.

Chapter 3 starts to explore this patent-based design process. An integrated process for designing around one existing patent through TRIZ is proposed. This process integrates patent design around strategies, innovative design methods in TRIZ and rules of patent infringement judgment to systematically design around existing patents and increase the patentability of results of innovation. Redesign of a portable magnetic impact tool to design around an existing patent is used to illustrate the integrated process. In Chapter 3, design matrices have not been used to represent the existing patents.

Chapter 4 discusses how the related patents obtained from patent analysis are symbolized using the concept derived from axiomatic design. Chapter 5 discusses the development of the design around algorithm and the integration with TRIZ to generate the real engineering design concept. The example of a portable magnetic impact tool is used again to illustrate the detailed steps of implementation and required considerations of the patent-based design process.

Chapter 6 gives another example to demonstrate the application process of this patent-based design process. Finally Chapter 7 gives conclusion on the accomplished studies, and the further works in this study.


Chang, W. T., Tseng, C. H., Wu, L. L., Creative mechanism design for a prosthetic hand,Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine, v.218, p.451-459, 2004.

Chen, A. and Chen, R., An adaptive design process generated by the integration of systematic design process and design patent protection mechanism,INTERNATIONAL JOURNAL OF GENERAL SYSTEMS, v.33, p.635-653, 2004.

Glazier, S. C., “Patent Strategies for Business,” Law & Business Institute, 1990.

Morgan Lewis & Bockius LLP, “Intellectual Property Handbook,” 5th Ed, PA: Morgan Lewis & Bockius LLP, 2000.

Nydegger, R. and Richards, J. W., Design Around Techniques,in Lundberg et al., Electronic and Software Patents, The Bureau of National Affairs, Inc., Washington, D.C., 2000.

Suh, N. P., “Axiomatic Design: Advances and Applications,” New York: Oxford University Press, 2001.

Ulrich, K.T., and Eppinger, S.D., “Product Design and Development,” McGraw-Hill, New York, 1995.

Zhang, H. T. and Chen, J. H., Application of extension theory and TRIZ to innovation design,Industrial Engineering Journal, v.7, p.33-37, 2004.